This invention relates to large fabric bags for transporting bulk quantities of particulate material and more particularly to bags containing particulate material which can be lifted by mechanical equipment having hooks or tines.
The advantages of large fabric bags for the carrying particulate material are clear. These bags are easily stored after the material has been emptied from the bags. These bags also provide for flexible handling of the bag until it is desired to fill the bags with the material to be transported. It is very critical that the bag be sufficiently strong to hold substantial amount of material. It is common for such bags to hold in excess of 1000 kilograms.
The name inventor of this application is the inventor or coinventor of a number of other patents in this field. His experience in this field causes his company to be a highly recognized leader in the field of bulk material handling.
Several different types of bags are known to the applicant herein. These bags involve use of certain types of material and special seams for the bags to provide the desired strength. These special seams are relatively complicated to manufacture and require a substantial amount of material to achieve the strength. It is desirable to make more efficient use of the material while maintaining the strength of the bag. It is also desirable to have the bag open enough to be filled easily and emptied easily.
Typically, the bags are desired to be of uniform square or rectangular horizontal cross-section. Of course, the square cross-section, according to geometric principles, provides the most area and volume for the amount of material used.
Generally, bags are required to be made of expensive, heavy-duty material to achieve desired strength. The fabric used for these bags is required to have a weight of at least eight ounces per square yard (271 grams per square meter) and a tensile strength of at least 400 pounds per square inch (28.2 kilograms per square centimeter). Such a strong fabric is required to make a bag of sufficient strength.
The bags of the prior art also require two people to load the bag onto the fork lift or other lifting apparatus. One person threads the loops onto the fork or hooks, while the other operates the lifting apparatus.
If a bag to carry bulk material can be manufactured more simply, and can use both less and inexpensive material while being easily handled by a forklift or similar apparatus can be developed; great advantages can be achieved.